Overflow device for water tank

Abstract

An aquarium overflow device capable of preventing adverse effects by suction noise of an overflow pipe. The aquarium overflow device according to the present invention is equipped with a water storing portion 52 for storing water W in an aquarium, an overflow pipe 54 extended upwardly in the water storing portion 52 and having an upper end opening for introducing the water W stored in the water storing portion 52 and a lower end opening for discharging the water which is open to a bottom wall side of the water storing portion 52 , and a sound preventing cover 47 provided in the water storing portion 52 so as to cover the entire region of the above-water portion of the overflow pipe 54.

The invention claimed is: 
     
       1. An aquarium overflow device for supplying water in an aquarium to an external device, the overflow device comprising:
 (a) an inverted U-shaped siphon pipe for supplying the water in the aquarium to an outside of the aquarium, the siphon pipe having an inlet side end portion to be disposed in the aquarium and an outlet side end portion to be disposed outside the aquarium, 
 wherein the siphon pipe has an air inlet portion formed at an inlet side pipe portion of the siphon pipe so as to be located above the inlet side end portion, 
 whereby, when a water level in the aquarium drops below the air inlet portion, air is introduced into the siphon pipe via the air inlet portion to thereby prevent water from being suctioned into the siphon pipe, and 
 (b) an inverted U-shaped discharge pipe having an inlet side end portion to be disposed outside the aquarium and an outlet side end portion to be disposed inside the aquarium, 
 wherein water forcibly supplied from an external device is introduced into the discharge pipe from the inlet side end portion and then discharged to the aquarium from the outlet side end portion, 
 wherein the discharge pipe is provided with a backflow preventing hole at an upper portion thereof, and 
 wherein, when forcible water supply from the external device is stopped, air is introduced into the discharge pipe from the backflow preventing hole to thereby prevent backflow of the water. 
 
     
     
       2. The aquarium overflow device as recited in  claim 1 , wherein the air inlet portion is formed by cutting out the inlet side portion of the siphon pipe. 
     
     
       3. The aquarium overflow device as recited in  claim 1 , further comprising a tank-outside water storing portion to be disposed along a side wall external surface of the aquarium, wherein the outlet side end portion of the siphon pipe is disposed in the tank-outside water storing portion so that the water in the aquarium is once stored in the tank-outside water storing portion and then supplied to an outside of the aquarium. 
     
     
       4. The aquarium overflow device as recited in  claim 1 , further comprising a tank-inside water storing portion which is to be disposed along a side wall inner surface of the aquarium and configured to introduce the water in the aquarium therein, wherein the inlet side end portion of the siphon pipe is disposed in the tank-inside water storing portion.